High-efficiency multivibrator circuits



Feb. 18, 1947.

0.15. M CLELLAN HIGH-EFFICIENCY ,MUL'I'I VIBRATOR CIRCUITS Filed July 28. 1943' Load INVENTOR Cyri/f/W: (Ye/lam,

WITNESSES: W

Patented Feb. 18, 194,7

Application July 28, 1943, SerialiNo; 4963521 'Myjinvention relates to electronic wave gen'er ato'rs', and in particular relates to an electronic ,waye generator of the multivibrator type. "'Multivibrator circuits have'found an increasing use in the radio artin which current pulses 'ofi'relatively short duration separated by a longer interval are generated." Such arrangements'of the "conventional type comprise two electronic tubes, one of 'which'conducts current onlywh'ile the current pulse which conducts current duringth'e longer inter Val between pulses.' The current flow in the lat ter tube is thus very n arly j'co'n'tinuous and repre- 'sents "a continued loss of power which may, be hundreds of "times greater than the power put into the useful pulses. 'Hen'ce such an arrangeinent is, in reality, highly inefilc'ient from an elec tri'cal power standpoint. f v

[The objects of my invention are to provide an arrangement for usinglelectronicjtubes to gener- 'ate' pulses of substantially the above-described type and which comprises two tubes, but in which both tubes are extinguished except duringthe relatively short time "of the current "pulse. 'Anoth'er'object of my 'invention'is" to provide an arrangement in which current through the tubes between the anodes and cathodes is limited only by .the electron emission of the cathode itself.

" Another objectof my invention isito provide a inultivibrator in which tubes of ,a given current tiona'l multivibrato'rs v A still further "objector my invention'is to' pro- .vide an electronic pulse generator which permits minal 3 of a direct currentvoltage source. The anodeu'of thetub'e I isriconnected directly to the anode of the tube :2 is connected to the terminal 3 through a resistor 4. Themathode of the tube 2 (is connected'to ground through the primaryfi a resistor 1 and a: second-'- ary48' of gaitransformerzhaving tclose couplingv: be tWEBIIZitSEWiD-diHE'SLiG and 8;. Thevterminal-iof the is flowing; andthe other of minal of the resistor ifl -and the control electrode of the 1tube:2' is connected th-rougha '-cap"acitor= l 5 with the cathode of the tube: A load circuit may have one of .its term'inalsiconnected mane cathode of uthe= tube 1L its-other terminal being grounded; alternatively, alload circuit mayflzhave one terminal connected totthe :anode. of theitube 2, its other terminal beingg-rounded: v

The windings 6 and 8 are preferably: wcundon of. this present application. windings 6' audit is such that a current flowing from the cathode of tube 2 to. ground .willfprm duce opposing magneticefiects on the magnetic The polarity nit ic 'Themode of operation: of the above-described arrangement is as follows:' The value of "the bias voltage impressed by 'th source IZ'OIL the control'electrodes is made such that when no If, now, a through the capacitor I 4 on the control electrode the latter tubeb'egins to condu'cncurage-of the source 3 across-the resistor 5; If a load circuit isconnected in shunt with the resistor-5; this voltage is accordingly impressed on the load; The'output voltage of the tube I appearing across the resistor 5 acts through the-condenser I 5% impress x ia 'mcre positive voltage on thecontro-l ;electrode of tube 2,

the current flow from skilled in the art.

' mentioned resistor,

thereby tending to increase the anode to the cathode of the latter. This in turn impresses a more strongly positive voltage pulse on the resistor I, which, acting through the condenser 9, makes the grid of the tube I more strongly positive. The current from anode to cathode in both tubes thus rises rapidly until it equals the full" electronic emission However, the condensers 9 and I soon acquire saturating charges which prevent them from continuing to impress the positive voltages present across the terminals of resistors 5 and 1, respectively, on the control electrodes of tubes 2 and I. Thereupon, the current fiow from anode to cathode of these two tubes begins sistors 5 and l are impressed on 15, thereby impressingnegative voltage pulses on the control electrodes of the tubes I and 2. These control electrodes thus react to further and .more rapidly decrease the current flow from anodes to cathodes of the tubes I and 2 with the result that current flow through both of these tubes quickly falls to zero, if the positive signalvoltage impressed through capacitor I4 on the control of electrode of tube 2 has ceased. The tubes I and 2 then remain nonconductive until the capacitor I4 on the input circuit impressed another positive voltage pulse on the control electrode of tube 2. 7 7

If desired, the load circuit may be connected from the anode of the tube 2 to ground instead of between'the cathode of tube I and ground, in

which case its polarity is the reverse of the po- 7 f larity with the last-mentioned connection.

specific embodiment While I have described one of the principles of my invention, it is of broader application in ways which I claim as my invention:

1. An impulse generator comprising a first grid controlled electron tube nected directly to the positive having its anode conterminal of a direct current voltage source and its cathode'connected to the negative terminal of said source through an impedance, a second grid controlledelectronic tube having its anode connected to the positive 3 terminal of said source through an impedance. and a cathode connected to the'negat'ive terminal of said source through a pair of closely coupled windings, and a second impedance, the control electrode oi the first said tube being connected to the end of the last-mentioned tube, the other end of the last-mentioned impedance being connected to the cathode of the first-mentioned tube, the control electrode of the second-mentioned tube being connected through a capacitor to the cathode of the first-mentioned .tube, a resistor connected between thecontrol electrodes of said tubes, a source of bias voltage connected to an intermediate point on the lastand means for impressing a signal on the control electrode of the secondmentioned tube. 7 7 7 1 2, An impulse generator comprising ,a first grid controlled electron tube having its anode connected directly to the positive terminal of a direct current voltage source and its cathode connectedto the negative terminal of said-source through an impedance, a second grid controlled electronic tube having its-anode connected to the of their respective cathodes;

'15 to decrease. When 7 this happens the decreased voltages across rethe control grids of tubes I and 2 by means of condensers 9 and will be evident to those v 5 impedance which is closer to the cathode of the second-mentioned closely coupledwinding s, the polarity of said.

that current flowing from 5 "windings being such the cathode of the second-mentioned tube to the negative terminal of :opposing magnetic effects in said a second impedance, the control electrode of' being connected to the end 1 the first said tube said source will produce winding, and

of the last-mentioned impedance which is closer to the cathode of other end the second-mentioned tube, the of the last-mentioned impedance being connected to the cathode of the first-mentioned tube, the mentioned tube pacitor to the cathode of the tube,

connected to an intermediate po mentioned resistor, and means control electrode of the secondbeing connected through a cafirst-mentioned a resistor connected between the control electrodes of said tubes, 9. source of bias voltage int on the lastfor impressing a signal on the control electrode of the'second-v mentioned tube.

3. An impulse generator comprising a first grid controlled electron tube having itsanode connected directly to the positive terminal of a direct current voltage source and its cathode connected to the negative terminal of said source through a resistor, a second electronic tube having grid controlled its anode connected to the positive terminal of said source through a resistor and a cathode connected terminal of said source through coupled windings, and a second r trol electrode of the i which is closer to the cathode tioned resistor being connected of the first-mentioned tube,

through a capacitor to the negative a pair of closely esistor, the confirst said tube being connected to the end of the last-mentioned resistor of the secondmentioned tube, the other end of thelast-mento the cathode the control electrode of the second-mentioned tube being connected to the cathode of the firstmentioned tube, a resistor connected between the control electrodes of bias voltage connected to an int on the last-mentioned resistor,

said tubes, a source of ermediate point and means for impressing a signal on the control electrode of the second-mentioned tube. 4. An impulse generator grid controlled electron comprising a first v tube having its anode connected directly to the positive terminal of a 7 direct current voltage source and its cathode connected to the negative terminal of said source through a resistor, a second grid positive terminal of said source sistor and. a cathode connected terminal of said source controlled electronic tube having its anode. connected to the through a re to the negative through a pair of closely coupled windings, the polarity of said windings being such that current flowing of the second-mentioned tube terminal of said source will pr magnetic efiects resistor, the control electrode 0 tioned resistor which is the second-mentioned in said winding,

from the cathode to the negative oduce opposing and a second i the first'said tube being connected to the end of the last mencloser to the cathode of tube, the other .end of the last-mentioned resistor being connected to the cathode of the first-mentioned tube, the control electrode of the'second-mentioned tube being connected through a capacitor to the oathode of the first-mentioned tube, nected between the control ele a resistor con- 7 ctrodes of said tubes, a source of bias voltage connectedto'an intermediate. point on the last -mentioned re- 5 sister, and means for impressing a signal on the control electrode of the second-mentioned tube. UNITED STATES PATENTS Number Name Date CYRIL MCCLELLAN- 2,266,668 Tubbs Dec. 16, 1941 REFERENCES CITED 2,275,016 Koch Mar. 3, 1942I The following references are of record in the file of this patent:

2,305,930 Martinalli Dec. 22, 1942 

